Floor structures comprising floor covering layer containing magnetic material



Sept 19, W67 .JONES ETAL 3,34 3

FLOOR STRUCTU C PR NG FLOOR COVERING LAYER CONTAINING M ETIC MATERIAL Filed Feb. 23, 1966 INVENTOR 2 WILLIAM H. JONES EMANUEL LAPREZIOSA 22 BY Mm, "726%,

ATTORNEYS United States Patent O 3,341,996 FLOOR STRUCTURES COMPRISING FLOOR COVERING LAYER CONTAINING MAG- NETIC MATERIAL William H. .lones, Mountain Side, N.J., and Emanuel Lapreziosa, Greensburg, Pa., assignors to The General Tire & Rubber Company, a corporation of Ohio Filed Feb. 23, 1966, Ser. No. 529,563 1 Claim. (Cl. 52-309) ABSTRACT OF THE DISCLOSURE Floor structures are formed by applying floor covering sheets or tiles having areas containing magnetized particles upon subfiooring which has magnetic material incorporated in it. The sheets or tiles provide a decorative floor covering layer which is retained upon the subflooring by magnetic attraction between the magnetic material of the subfiooring and the magnetized particle areas of the covering sheets or tiles.

This application is a continuation-in-part of copending application Ser. No. 234,08 1, filed by William H. Jones and Emanuel Lapreziosa on Oct. 30, 1962, now abandoned, entitled Structural Finishing Materials and Methods of Connecting the Finishing Materials to a Structural Substratum.

Background of the invention Floor tile and so-called linoleum are commonly used in buildings today to provide fioors with decorative and protective surfaces. Such covering tiles or sheets are generally applied over rough structural subsurfaces to provide, in simple and relatively inexpensive manner, suitable decorative finishes for the floors. In the remodeling of existing buildings, such floor coverings are frequently used to provide new decorative finishes to existing floors.

Although flooring tile and linoleum can be attached to subflooring by nails, staples or other fasteners, it is the usual practice to employ specialized adhesives for afiixing the floor covering to subflooring. However, disadvantages are associated with the existing methods of applying floor tile or other floor coverings, regardless of the method employed. Where an adhesive of paste-like condition is used to install tile or other floor covering over a concrete or other subsurface, many of the adhesives deteriorate with age, this being accelerated by exposure to moisture or alkali from the environment of the floor or cleaning operations. Other adhesives cause the floor covering to bubble or blister When exposed to moisture vapor. Other methods of connection applicable to floor tile, linoleum or the like require considerable skill and expense to install. Another disadvantage is that the known methods produce essentially permanent structures that are difficult to alter, repair or remove once installed.

Generally speaking, in modern building construction, the frame structures carry the support loading so that finish coverings are not subjected to strong forces which would tend to separate them from the supporting structure. This is especially true of floor tiling for the subflooring supports the tile and the only additional connection to the subfiooring required is that sufiicient to keep the tiles coplanar since the adjacent tiles support one another in a lateral direction. In US. Patent 2,474,767 to Walker, a method of setting floor tiles is disclosed where attachment is entirely dependent upon such floor and lateral support and the final lateral support is provided by an annular rectangular border. A problem with this particular method of floor installation is the requirement for 3,341,996 Patented Sept. 19, 1967 flooring. The building trade is desirous of avoiding the bubbling or blistering caused by vapor pressure in floor installations which employ adhesives to fix the floor covering to the substrate. Moreover, in view of everincreasing requirements for building rooms and partition construction today for the maximum degree of flexibility or mobility to deal with changing requirements or functions of the structure, it would be advantageous if fioor tiles or other floor coverings could be retained upon a subfiooring in satisfactory manner in a semi-permanent restrained condition permitting, however, the removal of the tile or other floor covering from the substrate without damage when renovation, remodeling or revision of a building structure is required.

Objects A principal object of this invention is the provision of new improvements in floor structures comprising a subflooring and a floor covering layer. Further improvements include:

(1) The provision of simple, but unique, arrangements for attaching flexible floor tiles, plastic floor covering sheets or comparable floor covering layers to subfiooring or equivalent substrates.

(2) The provision of floor covering layers in the form of tiles, continuous plastic sheets or equivalent floor covering layers which may be attached to structural subsurfaces with a minimum of skill and eifort.

(3) The provision of a magnetic attaching system for floor tiles or equivalent floor coverings which is durable, non-deteriorating and not subject to blistering o-r bubbling from the effects of moisture and chemical attack.

(4) The provision of floor structures provided with ornamental or decorative covering tiles or similar covering layers which may be easily changed, replaced or repaired as conditions or use requirements for the building area comprising the floor structure may demand.

(5) The provision of a system for attaching floor tiles or sheets to subflooring especially useful where such subflooring is composed partly or wholly of magnetic materials.

Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

Summary of the invention These objects are accomplished in accordance with the invention by the formation of floor structures comprising a subflooring having a first magnetic material affixed thereto, a floor covering layer comprising a decorative sheet disposed on the subfiooring with the decorative sheet having a second magnetic material afiixed thereto and with at least one of said magnetic materials being permanently magnetized whereby the covering layer is retained upon the subflooring by magnetic attraction between said first and second magnetic materials. Advantageously, the floor covering layer consists of tiles formed of a top decorative sheet and laminated thereto strips or full covering sheets of magnetic particles held in a plastic binder matrix. In a preferred embodiment, such magnetized floor tiles consist of a top decorative sheet of vinyl chloride polymer laminated to a bottom sheet comprising metal ferrite particles in a plastic binder matrix with the ferrite particles being permanently magnetized.

Brief description of the drawing A further description of the invention can be made with reference to the accompanying drawings in which:

FIGURE 1 is a fragmentary, sectional perspective view of an embodiment of the invention showing a portion of a floor structure comprising the subfiooring and covering surface;

FIGURE 2 is a fragmentary side sectional view of another floor structure of the invention showing a portion of floor tile and subflooring partly broken away: FIGURE 3 is an inverted perspective view of a single unit of a floor tile in accordance with the invention showing the lower surface of one embodiment of floor tile of the invention;

FIGURE 4 is a perspective view similar to FIGURE 3 showing the lower surface of another embodiment of floor tile in accordance with the invention; and

FIGURE 5 is yet another perspective view similar to FIGURE 3 showing the lower surface of yet another embodiment of fioor tile in accordance with the invention.

Referring now in detail to the drawings, the floor structure 1 comprises flexible floor tiles 2 and subfiooring 4. The subfiooring as shown is concrete; however, it may consist of plaster, plastic, metal lath or comparable construction material. Partly installed tile 6 is shown slightly warped for purposes of illustration, but is not intended to limit the material in the broad scope of the invention to flexible tiles or sheets since the invention contemplates the door covering layer may be rigid or flexible as the particular application may require.

Subfiooring 4 is coated with a suitable, hard drying magnetic particle vehicle material 8 which is spread on by suitable means and allowed to dry before tiles 2 are installed. Magnetic particle containing layer 8 afiixed to the subflooring carries a suspension of magnetic particles 10 such as iron filings, iron oxide powder, barium ferrite or the like. In use, the subflooring 4 is prepared by spreading on the hardenable coating material 8 by suitable means. In one embodiment of the invention, epoxy resin containing a suspension of iron filings was employed as the hardenabie coating 8, such plastic composition being troweled onto the subfiooring to form a smooth thin coating. After the coating 8 has dried to a sufiicient hardness. tiles 2 may be installed in contiguous abutting relationship with magnetic members 12 affixed to the lower surface of the tile 2 adjacent to the coating 8.

FIGURE 2 shows a different embodiment in accordance with the invention as a sectional side view of tile 2 and subfiooring 4. Magnetic particles 10 are shown cast in the upper surface of a subsurface 14. The material of the subsurface 14 shown is concrete, but it may be of any other materials suitable for the purpose. Magnetic particles 10 may be dispersed in the subsurface by adding them to the subsurface material while it is still in a plastic. state, e.g., after initialing troweling, but before final troweling. As an alternative, the magnetic particles 10 may be dispersed in the subsurface material during mixing thereof before it is put in place. After the subsurface 14 is hardened, tiles may be installed as in FIGURE 1.

FIGURE 3 shows an embodiment of a floor tile 2 in which magnetized members 12 are imbedded in the bottom surface of the tile 2 along two opposed sides of the tile. The magnetized strips 12 can be sections of magnetized iron or steel sheet or comparable units. Advantageously, however, the magnetized members 12 are formed of a major portion of finely subdivided magnetic particles dispersed in a minor portion of resinous binder matrix shaped into narrow strips which are imbedded by being pressed into the bottom surface of the tile 2 while the tile is in a plastic condition during a suitable stage. of its manufacture.

FIGURES 4 and 5 show that magnetized members of which the floor tiles 2 are comprised may be of any suitable configuration. In the embodiment shown in FIGURE 4, the magnetized portions of the floor tile comprise a peripheral edge section 16 formed, for example, of a strip of magnetic particle containing plastic composition having a width about one-quarter to one inch and a thickness about 10 to 25% of the total thickness of the tile 2. The inner portion 18 of the bottom surface of the floor tile, in the embodiment shown in FIGURE 4, is integral with the top surface 20 of the floor tile, but the exposed surfaces of portion 18 and edge section 16 are coplanar.

Referring to FIGURE 5, another embodiment of a floor tile 2 in accordance with the invention consists of a decorative top sheet 22 laminated to a bottom sheet 24 of thinner section consisting of a major portion of magnetic particles dispersed uniformly throughout a minor portion of resinous binder matrix.

Description of preferred embodiments A more complete understanding of the new floor structures and floor tiles, sheets or other floor covering materials in accordance with the invention may be had by reference to the following examples of actual workings conducted according to the invention. In these examples and throughout the remaining specification and claim, all parts or percentages are by weight unless otherwise specified.

EXAMPLE 1 Vinyl floor tiles of approximately mils thickness having a magnetized bottom surface for use in forming floor structures of the invention were prepared by the following procedure:

A thermoplastic composition was prepared by milling together parts of powdered barium ferrite and 27 parts of floor tile grade polyvinyl chloride resin. When the powdered barium ferrite had been homogeneously mixed with the polyvinyl chloride resin binder, the composition was passed through a 2-roll sheeting mill which was steam heated to a temperature of BOO-350 F. forming a continuous sheet approximately the width of the roll mill. The forming rolls of the mill were adjusted to deliver a sheet having a thickness of 10 mils.

In a separate operation, using a standard procedure of the trade for the formation of polyvinyl chloride fioor tile, a continuous plastic sheet comprising the normal proportions of plasticizer, filler and pigments to provide service grade floor tile was formed by processing the vinyl resin composition through a calender machine. The resulting vinyl plastic sheet having a thickness of approximately 75 mils was then cut into rectangular sections with a guillotine cutter and the barium ferrite containing sheet formed in the previous operation was cut into rectangular sections of similar size. Pairs of these rectangular sections, i.e., one of the thick sections of standard vinyl tile composition and one of the thin sections containing the barium ferrite, were faced together and then laminated in a single cavity mold by being pressed for five minutes at 200 p.s.i. and a temperature of 250 F. Then, the mold was cooled to room temperature, pressure was released and the laminated sheet was removed from the press.

The resulting laminated sheets were next magnetized by passage beneath a magnetizing element formed by a plurality of magnetizing poles spaced slightly apart from one another, alternating in polarity and in a line transverse to the axis of passage of the rectangular laminated sheets passed beneath the elongated magnetizing element. The magnetizing poles were in the form of electromagthe barium ferrite containing layer on the laminated vinyl plastic sheets after passing through the magnetizing device possessed a magnetic force, measured in gauss, of 210.

Following the magnetizing operation, the large rectangular sheets of magnetized laminated stock were cut with a guillotine cutter into standard 9 x 9 inch size floor tile.

In a second case, vinyl plastic floor tiles were prepared using the steps described above with two exceptions. First, the thin magnetizable bottom sheet for the laminated tile was prepared from a composition comprising 100 parts of barium ferrite and 48 parts of polyvinyl chloride resin. Secondly, the magnetic field force in the magnetizing element was controlled to'impart to the bottom magnetized surface of the resulting floor tile a magnetic force, measured in gauss, of 70.

In a third case, the initial operation was repeated except that the 10 mil bottom sheet was formed of a mixture of 100 parts powdered barium ferrite and 20 parts of chlorinated polyethylene. Floor tiles having good adhesion between the laminated layers were produced.

EXAMPLE 2 A series of magnetized vinyl floor tiles having a thickness of approximately 85 mils were prepared by general procedures as described in Example 1 using the specific compositions and conditions as indicated in the Table A.

TABLE A Sample Ferrite HYP PVC Thiclmess Temperature, F.

In the foregoing table, the column headings signify:

EXAMPLE 3 Floor tiles prepared in the first case of Example 1 described above were used to form a floor structure in a building constructed with concrete subflooring. Over the rough subflooring there was spread by hand trowel a covering about one-half inch thick of paste emulsion comprising about butadiene-styrene resin and 25% silica filler. Promptly after the paste had been spread smooth, iron metal filings were thickly sprinkled over the top of the coating. The area was again lightly troweled and then was left untouched until the coating had dried and hardened. The floor tiles of Example 1 were then applied in a staggered pattern and molding was installed around the base of the wall to complete the floor structure. The floor tiles laid flat when installed and all tiles remained firmly in place during continued use of the floored area.

The greatest flexibility in the construction of the new floor structures of the invention is obtained by permanently magnetizing the magnetic material which is afiixed to or carried by the floor covering layer. However, the magnetic material aflixed to the subflooring or comparable substrate may, instead, be the permanently magnetized material which is used to provide the magnetic attraction between the subflooring and the floor covering 6 layer. For example, powdered magnetic material may be incorporated, as indicated previously, in a binder matrix applied as a coating to the subflooring and the resulting magnetic particle containing coating may then be permanently magnetized.

Permanent magnetizing of sheets, films or coatings containing finely subdivided magnetic particles used as magnetic materials for either the fioor covering layer of the subflooring may be accomplished in any suitable fashion. Known methods and equipment for accomplishing such magnetization are disclosed in the prior art and technical publications, e.g., see US. Patent 3,051,988. Furthermore, this magnetization can be applied at any suitable stage in the formation of floor tile or other floor covering, e.g., during the formation of the bottom layer for the laminated floor tile, after formation of such bottom sheet, but before lamination with the top sheet, after complete formation of the laminated sheet or even after such laminated sheet has been cut into individual tiles.

The concepts of the invention may be applied to flooring tiles or other floor covering sheets of any desired area, thickness or flexibility, e.g., continuous sheets 2 to 6 feet in width. However, the invention has particular utility in the formation of flexible tile of standard size between 9 x 9 and 12 x 12 having a thickness of about 25 to 100 mils. Advantageously, with laminated tiles, the bottom sheet containing the magnetized particles has a thickness between about 10 to 25 mils while the top sheet comprising a standard polyvinyl chloride floor tile composition has a thickness between about 15 to mils.

The top portion of the new floor tiles or other floor covering materials may be made of any suitable plastic or rubber composition known in the art to be useful in forming such floor covering products. In the preferred embodiments of the invention, attachment of the magnetic particle containing film, sheet, strips or other areas may be accomplished by the heat and pressing methods as described in the foregoing examples. Although it is not known the exact nature of the bond between the tile and the sheet of magnetic material formed in such operations, it is believed that under the appropriate conditions of temperatures and pressures, the innerfacial surfaces of the two materials become soft and flow into one another creating a welding together of the surfaces. Pressures of to 1000 psi may advantageously be used with temperatures between about 250350 F. Alternatively, the aflixing of magnetic particle containing strips or sheets to the back of the floor covering tiles or sheets may be accomplished with the use of any suitable adhesive, cement or the like.

The relative amount of magnetic particles used in the formation of the new floor tiles or floor covering sheets may be varied as can also the proportion of such magnetic particles to plastic or resin materials used to form the binder matrix for the particles. Advantageously, lhOW- ever, strips, sheets or the like of magnetic material for the invention are made from thermoplastic compositions comprising 50 to 90% magnetic particles having an average size between about 1 to 100 microns and 10 to 50% by weight of chlorinated polyethylene, vinyl chloride polymer, sulfochlorinated polyolefins, or comparable resinous binder material.

The invention as described above provides new, unique floor structures which are simple, versatile and useful not only in creating new building construction, but also in renovating or remodeling existing structures. No difliculty is encountered in retention of the floor tile or other floor covering layer upon the subflooring or other substrate during the use of buildings containing such floor structures. However, the tiles or floor covering sheets can be removed without damage from the subflooring if this becomes desirable or necessary, e.g., in the installation of telephone, electrical or similar conduit in a subflooring, relocation of partitions or the like.

The subject matter sought to be protected by United States Letters Patent in view of the foregoing description is defined by the following claim.

We claim:

A floor structure comprising a subfiooring composed of a first magnetic material having magnetic particles dispersed in a matrix, a floor covering layer in the form of tiles about 25 to 100 mils in thickness, and consisting of a top decorative sheet of vinyl chloride polymer having a thickness of between about 15 and about 90 mils, and a bottom sheet laminated to and coextensive with said top sheet, having a thickness of between about 10 and about 25 mils and composed of permanently magnetized barium ferrite particles having a size of between 1 and 100 microns and constituting between about 50 and about 90% of said bottom sheet, and the remainder comprising a resinous binder, said tiles being retained upon said subflooring solely by magnetic attraction between said subfiooring and said tiles.

References Cited UNITED STATES PATENTS 1,113,555 10/1914 Haldeman 52-596 1,236,234 8/1917 Troje 317159 2,951,311 9/1960 Luther 5211 3,047,931 8/1962 Boettner 25131 3,095,668 7/1963 Dorsett 46241 3,121,977 2/1964 Bersudsky 52-614 FRANK L. ABBOTT, Primary Examiner.

I. L. RIDGILL, Assistant Examiner. 

